Organic waste, such as sludge, is widely used as a fertilizer. However, the waste is often conditioned to hygienization before it can be used as a fertilizer. The purpose of hygienization is to remove pathogenic microorganisms from biowaste, thus improving the usability of the biowaste as a fertilizer. Common methods for the hygienization include heating of the biowaste or, alternatively, exposing the biowaste to natural hygienization, according to which the biowaste decomposes over time. Both of these types of hygienization solutions are complicated processes and require several separate machines and vehicles which each perform certain steps of the process towards hygienization. This is clearly not an optimal solution for performing the hygienization. Thus, it is important to provide a solution for performing the hygienization in a more optimal manner.